A dimmer unit is equipped with a first light detection unit that modulates the light intensity of composite laser light emitted from a composite laser light emission unit and detects the light intensity of the composite laser light before entering the dimmer unit, and a second light detection unit that detects the light intensity of the composite laser light after entering the dimmer unit. The light intensity characteristic for each color in the composite laser light emission unit is calculated on the basis of the light intensity detected by the first light detection unit, and the white balance of each color in the composite laser light emission unit is adjusted on the basis of the light intensity detected by the second light detection unit.